This invention relates to a new alcohol composition suitable for mixing with gasoline, to a gasoline composition containing same and to a process for its preparation.
It is well known to incorporate methanol into gasoline for the purpose of increasing the amount of useful fuel. Unfortunately, the presence of a small amount of water in a methanol/gasoline mixture causes separation of the methanol and gasoline phases. In order to overcome this problem, higher alcohols have been added to methanol/gasoline mixtures, and the compositions so obtained are able to tolerate a much greater amount of water than a simple methanol/gasoline mixture.
U.S. Pat. No. 4,298,354 describes an alcohol composition for mixing with gasoline comprising at least 40 percent of methanol, the remainder of said composition comprising higher alcohols, the distribution of which on a methanol-free basis is
C.sub.2 --4 to 25 weight percent, PA1 C.sub.3 --0.1 to 25 weight percent preferably 9 to 25 percent, PA1 C.sub.4 --0.5 to 70 weight percent preferably 40 to 70 percent, PA1 C.sub.5 --0.1 to 12 weight percent, PA1 C.sub.6 --0.1 to 10 weight percent. PA1 a is 0.5 to 2.5, PA1 b is 0.01 to 1.0, PA1 c is 0.05 to 0.9 and PA1 x is a number such that the valence requirements of the other elements for oxygen is satisfied. PA1 C.sub.1 --35 to 75 percent PA1 C.sub.2 --2 to 5 percent (2.9 to 21.9 percent) PA1 C.sub.3 --3 to 12 percent (4.8 to 41.4 percent) PA1 C.sub.4 --10 to 30 percent (19.2 to 75 percent) PA1 C.sub.4+ --5 to 25 percent (9.6 to 62.5 percent) PA1 C.sub.2 --about 10 to 90 weight percent PA1 C.sub.3 --about 15 to 60 weight percent PA1 C.sub.4 --about 0.5 to 35 weight percent PA1 C.sub.5 --about 0 to 15 weight percent PA1 C.sub.6 --about 0 to 15 weight percent PA1 a is from 0.01 to 5.0; PA1 b is from 0 to 5.0 with the proviso that when M is Th the value of b is less than 1; PA1 c is a number up to 5.0 selected so that the catalyst contains more than 2 percent by weight of Metal A; PA1 x is a number such that the valence requirements of the other elements for oxygen are satisfied. PA1 C.sub.2 --about 10 to about 90 percent, PA1 C.sub.3 --about 15 to about 60 percent, preferably about 25 to about 55 percent, PA1 C.sub.4 --about 0.5 to about 35 percent, preferably about 8 to about 30 percent, PA1 C.sub.5 --about 0 to about 15 percent, PA1 C.sub.6 --about 0 to about 15 percent. PA1 C.sub.2 --10 to 25 percent, PA1 C.sub.3 --40 to 60 percent, PA1 C.sub.4 --10 to 25 percent, PA1 C.sub.5 --5 to 15 percent, PA1 C.sub.6 --0 to 5 percent, and, PA1 C.sub.2 --40 to 70 percent, PA1 C.sub.3 --25 to 45 percent, PA1 C.sub.4 --5 to 15 percent, PA1 C.sub.5 --0 to 10 percent, PA1 C.sub.6 --0 to 5 percent.
This patent further discloses a modified gasoline composition containing a homogeneous solution of gasoline and a composition of the above alcohols. This patent further discloses a process for the preparation of the above described alcohol composition which process comprises contacting carbon monoxide and hydrogen with an oxide complex catalyst of formula EQU Cu.sub.a ThM.sub.b A.sub.c O.sub.x
wherein M is one or more of Ca, Mo, Rh, Mn, Pt, Ce, Cr, Zn, Al, Ti, La, V, U, Ru, Re and Pd and
Further, Great Britain Patent Application No. 2 083 469A describes an alcohol composition containing the following
The figures in brackets are on a methanol-free basis.
For gasoline blending it is desirable that an alcohol composition contains alcohols of carbon number high than C.sub.1 in order to achieve good cloud point properties. However, when considered from its production from syn gas it is desirable that alcohols of carbon number 4 and higher do not form a significant proportion of the product, since for each molecule of carbon monoxide used in building the carbon chain, an atom of oxygen must be discarded either in the form of water or carbon dioxide with consequent loss of feed. It is desirable to obtain an alcohol composition containing alcohols of carbon number at least 2 but in which the proportion of alcohols of carbon number 3 is high in relation to the higher carbon number alcohols.
It is therefore an object of the present invention to provide a new alcohol composition suitable for mixing with gasoline in which the percent by weight of C.sub.3 alcohols is at least 1.25 times that of the C.sub.4 alcohols and in addition a gasoline modified by the incorporation of this new alcohol composition.